1. Field of the Invention
This invention relates to cross-linked conductive polymers and more particularly to antistat layers employing the cross-linked conductive polymers. Additionally, the invention relates to light sensitive elements having at least one antistat layer.
2. Description of Related Art
Schadt, U.S. Pat. No. 4,225,665, discloses an antistatic composition for photographic films wherein a conductive polymer having carboxyl groups and a hydrophobic polymer containing carboxyl groups are cross-linked with a polyfunctional aziridine.
Hardam et al, U.S. Pat. No. 4,668,748, discloses a cross-linkable conductive copolymer of a monomer of sodium styrene sulfonate type and a vinyl amine monomer.
Because of the electrostatic charges that build up on polymeric articles as they move in contact with other surfaces of high dielectric constant, it has been necessary to provide a conductive layer on polymeric articles in order to prevent the build up of charges. This problem is particularly acute in photographic applications, both during the preparation thereof and during use and development, because during the preparation it is undesirable to have static discharge that will expose localized areas of the light sensitive recording media. Subsequently, both during the exposure cycle and the development cycle, static charges are unwanted because they attract dirt and dust particles which appear as imperfections in the final presentation of the developed image, whether it be in the form of a print or projected image. The two patents mentioned above, provide antistatic properties during the preparation and subsequently during processing of the film and are for that reason defined as having permanent antistat properties.
It is also desirable to provide antistat coatings for light sensitive elements wherein the antistat layers also serve as subbing layers for subsequently applied layers in the recording element, overcoat layer and the like. When employed as subbing layers, in addition to having antistat properties, the layers should also promote adhesion. When serving as an overcoat, the layer should also provide the recording element a measure of protection with regard to abrasion. Abrasion is an ever present problem in photographic films, particularly because in all stages of its preparation, use and development, the film encounters other objects such as rollers and the like. Indeed in motion picture film, for example, the film is constantly moved passed a variety of elements in the projection apparatus which can cause imperfections as a result of contact therewith. Further, as the film is utilized in projection apparatus, it attracts dust particles from the environment which when projected become enlarged. It is desirable to remove such particles and therefore it is necessary that the film have a measure of abrasion resistance in order to withstand brushing or the like to accomplish this purpose.
It is therefore desirable to provide an antistat layer in a photographic element that not only is of the proper conductivity to prevent the build up of electrostatic charges but also one which also enhances its function as a subbing layer to promote adhesion or as an overcoat to withstand the various forces applied to the surface of the particular photographic element.